U.S. patent number 8,896,152 [Application Number 13/173,405] was granted by the patent office on 2014-11-25 for systems and methods for operating an uninterruptible power supply.
This patent grant is currently assigned to Schneider Electric IT Corporation. The grantee listed for this patent is Mirza A. Beg, Venkatraman Chennakesavan, Rajesh Ghosh, Michael J. Ingemi, Indra Prakash, David E. Reilly. Invention is credited to Mirza A. Beg, Venkatraman Chennakesavan, Rajesh Ghosh, Michael J. Ingemi, Indra Prakash, David E. Reilly.
United States Patent |
8,896,152 |
Beg , et al. |
November 25, 2014 |
Systems and methods for operating an uninterruptible power
supply
Abstract
An uninterruptible power supply includes a first input to
receive input power from an input power source, an output to
provide output power, a switch, a first logic power supply coupled
to the switch, a back-up power source, a charger, a main logic
power supply and power converter circuitry. The switch is
configured to close when a characteristic of the input power is
within a selected range. The first logic power supply is coupled to
the switch and configured to receive input power from the input
power source when the switch is closed. The first logic power
supply has a first DC output. The back-up power source has a second
DC output and is coupled to the first DC output at a common node.
The charger has a third DC output and is coupled to the common
node. The main logic power supply is coupled to the common node and
is configured to receive at least one of the first DC output, the
second DC output and the third DC output. The power converter
circuitry is coupled to the backup power source and the first input
and is configured to provides the output power derived from at
least one of power at the first input and power from the backup
power source.
Inventors: |
Beg; Mirza A. (Pepperell,
MA), Chennakesavan; Venkatraman (Groton, MA), Ingemi;
Michael J. (Norwood, MA), Reilly; David E. (Concord,
MA), Ghosh; Rajesh (Bangalore, IN), Prakash;
Indra (Bangalore, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Beg; Mirza A.
Chennakesavan; Venkatraman
Ingemi; Michael J.
Reilly; David E.
Ghosh; Rajesh
Prakash; Indra |
Pepperell
Groton
Norwood
Concord
Bangalore
Bangalore |
MA
MA
MA
MA
N/A
N/A |
US
US
US
US
IN
IN |
|
|
Assignee: |
Schneider Electric IT
Corporation (West Kingston, RI)
|
Family
ID: |
46545466 |
Appl.
No.: |
13/173,405 |
Filed: |
June 30, 2011 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20130002024 A1 |
Jan 3, 2013 |
|
Current U.S.
Class: |
307/64; 307/66;
307/65 |
Current CPC
Class: |
H02J
9/061 (20130101); H02J 1/108 (20130101) |
Current International
Class: |
H02J
9/00 (20060101) |
Field of
Search: |
;307/64 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
10-2010-0131342 |
|
Dec 2010 |
|
KR |
|
2010/070676 |
|
Jun 2010 |
|
WO |
|
Other References
Notification of Transmital of the International Search Report and
the Written Opinion of the International Searching Authority from
corresponding PCT/US2012/044652 mailed Jun. 10, 2013. cited by
applicant.
|
Primary Examiner: Barnie; Rexford
Assistant Examiner: Vu; Toan
Attorney, Agent or Firm: Lando & Anastasi, LLP
Claims
What is claimed is:
1. An uninterruptible power supply comprising: a first input to
receive input power from an input power source; an output to
provide output power; a switch configured to close when a
characteristic of the input power is within a selected range; a
first logic power supply coupled to the switch, configured to
receive input power from the input power source when the switch is
closed, and having a first DC output; a backup power source having
a second DC output and coupled to the first DC output at a common
node; a charger having a third DC output and coupled to the common
node; a main logic power supply coupled to the common node and
configured to receive the first DC output, the second DC output and
the third DC output; and power converter circuitry coupled to the
backup power source and the first input and configured to provide
the output power derived from at least one of power at the first
input and power from the backup power source.
2. The uninterruptible power supply of claim 1, further comprising:
a main controller for controlling operation of the uninterruptible
power supply; and a communication circuit configured to allow a
user to select a mode of operation of the uninterruptible power
supply; wherein the main logic power supply is coupled to the main
controller and the communication circuit and further configured to
provide power to the main controller and the communication
circuit.
3. The uninterruptible power supply of claim 2, further comprising
a second logic power supply coupled to the switch, configured to
receive input power from the input power source when the switch is
closed, and configured to power the communication circuit.
4. The uninterruptible power supply of claim 1, wherein the power
converter circuitry includes: an AC-to-DC converter coupled to the
first input and having a fourth DC output; and an inverter coupled
to the AC-to-DC converter and the UPS output.
5. The uninterruptible power supply of claim 4, wherein the charger
is further coupled to the AC-to-DC converter and the backup power
source, and wherein the charger receives the fourth DC output and
provides the third DC output to the backup power source to charge
the backup power source.
6. The uninterruptible power supply of claim 1, further comprising
a second input to receive power from a second input power source,
wherein the second input is selectively coupled to the UPS output
to provide output power from the second input power source.
7. A method for providing uninterrupted power from a power supply
having a first input to receive input power and a UPS output from
which UPS output power is provided, the method comprising:
providing power from the first input to a first logic power supply
having a first DC output when the input power at the first input is
acceptable; providing the first DC output to a main logic power
supply having an MLPS output; providing the MLPS output to a main
controller and a communication circuit; turning on, with the main
controller, a charger having a third DC output; providing the third
DC output to the main logic power supply; turning off the first
logic power supply; determining whether the charger is operating
acceptably; if the charger is not operating acceptably, turning on
the first logic power supply; and providing output power at the UPS
output.
8. The method of claim 7, further comprising: providing power to
the main logic power supply from a back-up power source having a
second DC output upon loss of the input power.
9. The method of claim 8, further comprising: charging the back-up
power source with the third DC output.
10. The method of claim 7, further comprising: providing power from
the first input to a second logic power supply; providing power to
the communication circuit from the second logic power supply in a
sleep mode of operation; and turning off the first logic power
supply, the main logic power supply, the main controller and the
charger in the sleep mode of operation.
11. The method of claim 7, further comprising: providing power from
the first input to an AC-to-DC converter having a fourth DC output;
providing the fourth DC output to an inverter; and providing the
fourth DC output to the charger.
12. The method of claim 7, further comprising: providing power from
a second input to the first logic power supply when the input power
at the first input is not acceptable.
13. An uninterruptible power supply comprising: a first input to
receive input power from an input power source; a backup power
source having a DC output coupled to a common node; a UPS output
configured to provide output power derived from at least one of the
input power and power from the backup power source; a charger
coupled to the backup power source through the common node; a main
controller for controlling operation of the uninterruptible power
supply; a communication circuit configured to allow a user to
select a mode of operation of the uninterruptible power supply; a
main logic power supply coupled to the common node and configured
to receive power derived from the input power source, the charger,
and the backup power source, and further configured to provide
power to the main controller and the communication circuit; and
means for providing power to the main logic power supply in a start
up mode of operation from the input power bypassing the backup
power source and the charger.
14. The uninterruptible power supply of claim 13, further
comprising means for providing power to the communication circuit
in a sleep mode of operation from the input power bypassing the
backup power source and the charger.
15. The uninterruptible power supply of claim 14, further
comprising means for exiting the sleep mode of operation using the
communication circuit.
16. The uninterruptible power supply of claim 13, further
comprising means for providing power to the main logic power supply
through the charger in a green mode of operation bypassing a first
logic power supply.
17. The uninterruptible power supply of claim 13, further
comprising means for providing power to the main logic power supply
in a green mode of operation bypassing the backup power source and
the charger.
18. The uninterruptible power supply of claim 13, further
comprising means for providing power to the main logic power supply
in a bypass mode of operation bypassing the first input.
19. The uninterruptible power supply of claim 13, further
comprising means for providing the UPS output in a bypass mode of
operation bypassing the backup power source, the charger and the
main logic power supply.
Description
BACKGROUND
An uninterruptible power supply (UPS) is used to provide backup
power to an electrical device, or load, when the primary power
source, or mains, fails. Typical loads include computer systems,
but other loads, such as heating/cooling/ventilation systems,
lighting systems, network switches and routers, and security and
data center management systems may also be powered by a UPS. A UPS
designed for data center or industrial use may provide backup power
for loads for several hours.
A UPS unit typically includes a logic power supply (LPS) and one or
more batteries. The LPS is designed to receive power from the
batteries or from a battery charger. Additionally, the batteries
act as a power source when AC mains power is unavailable. The
battery charger, which converts AC power to DC power, may be
included in the UPS to charge the batteries when AC mains is
available to ensure that backup power will be available when
needed. The UPS may also include a control unit for automatically
managing the operation of the UPS and the power conversion
functions.
SUMMARY
According to one aspect, systems and methods for starting a UPS
without a battery are provided. According to another aspect,
systems and methods are provided for designing a UPS with a sleep
mode, in which the UPS draws minimal power. According to another
aspect, a UPS having a green or high energy efficient mode is
provided.
According to one aspect, an uninterruptible power supply includes a
first input to receive input power from an input power source, an
output to provide output power, a switch, a first logic power
supply, a backup power source, a charger, a main logic power
supply, and power converter circuitry. The switch is configured to
close when a characteristic of the input power is within a selected
range. The first logic power supply is coupled to the switch and
configured to receive input power from the input power source when
the switch is closed. The first logic power supply has a first DC
output. The backup power source has a second DC output and is
coupled to the first DC output at a common node. The charger has a
third DC output and is coupled to the common node. The main logic
power supply is coupled to the common node and is configured to
receive at least one of the first DC output, the second DC output
and the third DC output. The power converter circuitry is coupled
to the backup power source and the first input and is configured to
provide the output power derived from at least one of power at the
first input and power from the backup power source.
According to one embodiment, the uninterruptible power supply
includes a main controller for controlling operation of the
uninterruptible power supply and a communication circuit configured
to allow a user to select a mode of operation of the
uninterruptible power supply. The main logic power supply may be
coupled to the main controller and the communication circuit. The
main logic power supply may be configured to provide power to the
main controller and the communication circuit. The uninterruptible
power supply may include a second logic power supply coupled to the
switch, configured to receive input power from the input power
source when the switch is closed, and configured to power the
communication circuit.
According to another embodiment, the power converter circuitry
includes an AC-to-DC converter coupled to the first input and
having a fourth DC output and an inverter coupled to the AC-to-DC
converter and the UPS output. The charger may be further coupled to
the AC-to-DC converter and the backup power source, and the charger
may receive the fourth DC output and provide the third DC output to
the backup power source to charge the backup power source.
According to another embodiment, the uninterruptible power supply
includes a second input to receive second power from a second input
power source. The second input may be selectively coupled to the
UPS output to provide output power from the second power
source.
According to one aspect, a method for providing uninterrupted power
from a power supply is provided. The uninterrupted power supply has
a first input to receive input power and a UPS output from which
UPS output power is provided. The method includes providing power
from the first input to a first logic power supply having a first
DC output when the input power at the first input is acceptable,
providing the first DC output to a main logic power supply having a
MLPS output, providing the MLPS output to a main controller and a
communication circuit, turning on, with the main controller, a
charger having a third DC output, providing the third DC output to
the main logic power supply, turning off the first logic power
supply, and providing output power at the UPS output.
In one embodiment, the method includes providing power to the main
logic power supply from a back-up power source having a second DC
output upon loss of the input power. The method may include
charging the back-up power source with the third DC output.
According to one embodiment, the method includes determining
whether the charger is operating acceptably, and if the charger is
not operating acceptably, turning on the first logic power supply.
According to another embodiment, the method includes providing
power from the first input to a second logic power supply,
providing power to the communication circuit from the second logic
power supply in a sleep mode of operation, and turning off the
first logic power supply, the main logic power supply, the main
controller and the charger in the sleep mode of operation.
According to another embodiment, the method includes providing
power from the first input to an AC-to-DC converter having a fourth
DC output, providing the fourth DC output to an inverter, and
providing the fourth DC output to the charger. According to a
further embodiment, the method includes providing power from a
second input to the first logic power supply when the input power
at the first input is not acceptable.
According to one aspect, an uninterruptible power supply is
provided, including a first input to receive input power from an
input power source, a backup power source, a UPS output, a charger,
a main controller, a communication circuit, a main logic power
supply, and means for providing power to the main logic power
supply in a start up mode of operation from the input power
bypassing the backup power source and the charger.
The backup power source has a DC output coupled to a common node.
The UPS output is configured to provide output power derived from
at least one of the input power and power from the backup power
source. The charger is coupled to the backup power source through
the common node. The main controller controls operation of the
uninterruptible power supply. The communication circuit is
configured to allow a user to select a mode of operation of the
uninterruptible power supply. The main logic power supply is
coupled to the common node, to receive input power from at least
one of the charger and the backup power source and is configured to
provide power to the main controller and the communication
circuit.
In one embodiment, the uninterruptible power supply includes means
for providing power to the communication circuit in a sleep mode of
operation from the input power bypassing the backup power source
and the charger. According to another embodiment, the
uninterruptible power supply includes means for exiting the sleep
mode of operation using the communication circuit. In another
embodiment, uninterruptible power supply includes means for
providing power to the main logic power supply through the charger
in a green mode of operation bypassing a first logic power supply.
According to a further embodiment, the uninterruptible power supply
includes means for providing power to the main logic power supply
in a green mode of operation bypassing the backup power source and
the charger. According to another embodiment, the uninterruptible
power supply includes means for providing power to the main logic
power supply in a bypass mode of operation bypassing the first
input. In another embodiment, the uninterruptible power supply
includes means for providing the UPS output in a bypass mode of
operation bypassing the backup power source, the charger and the
main logic power supply.
BRIEF DESCRIPTION OF THE FIGURES
The accompanying drawings are not intended to be drawn to scale. In
the drawings, each identical or nearly identical component that is
illustrated in various figures is represented by a like numeral.
For purposes of clarity, not every component may be labeled in
every drawing. In the drawings:
FIG. 1 is a schematic diagram of an existing LPS architecture;
FIG. 2 is a schematic diagram of a UPS design in accordance with an
embodiment of the invention;
FIG. 3 shows a flow chart of a method of powering the main LPS in a
UPS in accordance with an embodiment of the invention;
FIG. 4 shows a flow chart of a method of switching a UPS to a sleep
mode of operation in accordance with an embodiment of the
invention; and
FIG. 5 is a schematic diagram of an alternative UPS design in
accordance with an embodiment of the invention.
DETAILED DESCRIPTION
Embodiments of this invention are not limited in their application
to the details of construction and the arrangement of components
set forth in the following description or illustrated in the
drawings. Embodiments of the invention are capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, the phraseology and terminology used herein is
for the purpose of description and should not be regarded as
limiting. The use of "including," "comprising," or "having,"
"containing," "involving," and variations thereof herein, is meant
to encompass the items listed thereafter and equivalents thereof as
well as additional items.
Various embodiments of the present disclosure relate to logic power
supply (LPS) architectures for an uninterruptible power supply
(UPS). An existing LPS architecture 100 is shown in FIG. 1. Mains
power 102 is input to a charger 104. The charger 104 outputs power
to a battery 106 and a LPS 108. The LPS 108 provides bias power to
a UPS control and user interface 110 and to the charger 104. The
battery 106 provides the initial start-up power to the LPS 108. The
battery 106 receives its charge from the charger 104. If the mains
power 102 is unavailable, the charger 104 is unavailable, and the
LPS 108 begins to drain the battery 106. When the mains power 102
becomes available again, the charger 104 recharges the battery 106.
Since the battery 106 provides the initial start-up power to the
LPS 108, if the battery 106 becomes completely drained, the LPS 108
does not start up when mains power 102 becomes available again.
When the mains power 102 becomes available after the battery 106 is
drained, the LPS 108 may not be turned on if the battery 106 is
drained beyond a LPS 108 turn-on threshold. If the LPS 108 is not
turned on, it does not provide bias power to the charger 104 and
UPS control 110, and the UPS 100 will not wake up to process input
power.
A UPS unit typically includes one logic power supply (LPS), which
is designed to receive power only from one or more batteries. As
described above, when AC mains power is unavailable, the LPS
continues to run on battery power. When AC mains power is
available, it is directed in part to a battery charger, which
charges the batteries and provides power to the LPS. However, if AC
power is unavailable and the batteries become fully discharged, the
LPS turns off. Additionally, when AC mains power becomes available
again, the LPS does not immediately turn on, since the batteries
draw the charge provided from the charger. In existing UPS units,
the LPS cannot turn on until the batteries are sufficiently
recharged.
FIG. 2 shows a UPS 200 according to one embodiment of the
invention. The UPS 200 includes a first relay 206, an AC detection
circuit 204, a battery 216, a first LPS 210, a second LPS 208, a
main LPS 212, a main controller 218 and a communication circuit
214. The UPS 200 also includes a power factor correction (PFC)
converter 222, a charger 220, an inverter 234, and an output 230.
The UPS 200 receives input power from an AC mains power supply 202
(single- or multi-phase) and outputs power at line 230. The output
power at line 230 may be single- or multi-phase. The AC mains power
supply 202 is coupled to the AC detection circuit 204 and the first
relay 206, and the AC detection circuit 204 is coupled to the first
relay 206. The first relay 206 is coupled to the first LPS 210 and
the second LPS 208. The first LPS 210 is coupled to the main LPS
212. The battery 216 is also coupled to the main LPS 212. According
to one example, the first LPS 210 may be called an auxiliary LPS
(ALPS) and the second LPS 208 may be called an economy LPS
(ELPS).
The AC detection circuit 204 is configured to monitor the AC input
voltage at start-up from the AC mains power supply 202. According
to one embodiment, if the AC input voltage is within an acceptable
range, the AC detection circuit 204 closes the first relay 206 to
couple the AC mains power supply 202 to the first LPS 210 and the
second LPS 208. In one example, an acceptable range for the AC
mains power supply 202 is between approximately 100 Vrms and
approximately 300 Vrms.
The communication circuit 214, in one embodiment provides a
communications interface to a user interface of the UPS 200. In
addition, the communication circuit 214 may be coupled to one or
more communication networks to allow the UPS 200 to be monitored
and/or controlled from remote devices over one or more
networks.
When AC input voltage is available and within an acceptable range
at startup, the second LPS 208 remains in an OFF state. The first
LPS 210 receives the AC input voltage and the first LPS 210
converts the input AC voltage to a DC voltage and provides the DC
voltage to the main LPS 212. According to one embodiment, the first
LPS 210 and the main LPS 212 power up automatically when AC mains
power is available at startup. In one example, the first LPS 210
outputs DC power between about 225 Vdc to about 450 Vdc. The first
LPS 210 outputs the DC power to the main LPS 212. The main LPS 212
powers the main controller 218 and the communication circuit
214.
FIG. 3 shows a flow chart of a method 300 of powering the UPS 200
at startup, according to an embodiment of the invention. At block
302, the AC detection circuit 204 determines whether the AC input
voltage from an AC mains power supply 202 is acceptable. If the AC
input voltage is not acceptable at block 302, at block 304 the
battery 216 provides power to the main LPS 212. The main LPS powers
the main controller 218 and the communication circuit 214 (block
324). At block 326, the battery 216 provides the UPS output power
at line 230.
If the AC input voltage is acceptable at block 302, at block 306
the AC input voltage is coupled to the first LPS 210. The first LPS
210 may be an auxiliary LPS. At block 308, the first LPS 210
converts the AC input voltage to DC voltage and provides DC voltage
to the main LPS 212. At block 310, the main LPS 212 provides power
to the main controller 218 and the communication circuit 214.
At block 312, the main controller 218 powers up the PFC converter
222 and the battery charger 220, and provides output power from the
UPS 200 derived from the input power. At block 314, the main
controller 218 determines whether the battery charger 220
successfully turned on. If the battery charger 220 is on, at block
316 the battery charger 220 provides power to the main LPS 212. At
block 318, the main controller 218 turns off the first LPS 210, and
the main LPS 212 receives power from the battery charger 220. The
main controller 218 monitors the battery charger 220 at block 314,
to ensure that the battery charger 220 remains on. At block 314, if
the battery charger 220 fails or stops providing power to the main
LPS 212, then at block 320, the communication circuit 214 turns on
the first LPS 210 to power the main LPS 212 from the input AC
voltage.
In the embodiment shown in FIG. 2, the PFC 222 includes a DC-DC
converter. The PFC 222 also includes an AC-DC converter. The PFC
222 receives input voltage from the AC mains power supply 202 when
the second relay 228 is closed. The PFC 222 is shown coupled to the
battery 216 and the inverter 234. According to one feature, the
main controller 218 controls the PFC 222 and the inverter 234. In
line mode of operation, under control of the main controller 218,
the PFC 222 receives the AC input voltage and provides positive and
negative DC voltages at lines 242 and 244. In a battery mode of
operation, upon loss of input AC power, the PFC 222 generates the
DC voltages at lines 242 and 244 from the battery 216. The inverter
234 receives the DC voltages from the PFC 222 and provides an
output AC voltage at line 230. In the embodiment shown in FIG. 2
only one battery is shown, however, in different embodiments, the
battery 216 may be implemented using a combination of batteries
coupled in parallel and/or in series to provide the voltage and
capacity necessary for a given implementation.
The main controller 218 provides monitoring and control of
components of the UPS 200. In FIG. 2, the controller 218 is shown
as coupled only to the main LPS 212. However, according to one
embodiment, the main controller 218 is coupled to the PFC 222 and
the inverter 234. According to another embodiment, the main
controller 218 may be coupled to all major components of the UPS
200 and may also be coupled to numerous sensing devices to monitor
operational parameters of the UPS 200.
According to one embodiment, when the AC power is unavailable, the
battery 216 may be used to turn on the UPS 200 by first turning on
the main LPS 212. A user may turn on the main LPS 212 by pressing
the switch 224. The switch 224 causes the main LPS 212 to power up
using power from the battery 216. If the AC mains power 202
subsequently becomes available, the battery charger 220 provides
power to the main LPS 212 and charges the battery 216. If the
charger 220 fails, the communication circuit 214 turns on the first
LPS 210, which provides power to the main LPS 212 from the AC mains
power supply 202.
According to various embodiments, the UPS 200 includes multiple
modes of operation. For example, the UPS 200 includes first and
second green modes of operation, in which the UPS 200 consumes less
power and is more energy efficient. In another example, the UPS 200
includes a standby mode and a sleep mode, in which the UPS 200
consumes little power and is energy efficient. The UPS 200 may also
include an Emergency Power Off mode of operation. In one example,
the UPS 200 is configured to transfer to a bypass mode of operation
if the AC mains power supply 202 fails.
According to one embodiment, the UPS 200 includes a first green
mode option. In the first green mode, the main LPS 212 receives
power from the charger 220 and the first LPS 210 is turned off. The
PFC 222 receives power from the AC mains and the PFC 222 provides
power to the charger 220. The main LPS 212 provides power to the
main controller 218 and the communication circuit 214. The PFC 222
provides power to the inverter 234 over lines 242 and 244, and the
inverter 234 provides the UPS 200 output voltage at line 230. The
first LPS 210 and the second LPS 208 remain in an OFF state in the
first green mode.
According to another embodiment, the UPS 200 includes a second
green mode option. In the second green mode, the main controller
218 turns off the charger 220. The communication circuit 214 turns
on the first LPS 210. The first LPS 210 provides power to the main
LPS 212 through a first diode 226. According to one feature,
turning off the charger 220 reduces tare losses. In one embodiment,
the PFC 222 provides power to the inverter 234 over lines 242 and
244, and the inverter 234 provides the UPS 200 output voltage at
line 230. According to another embodiment, the main controller 218
turns off the PFC 222, and output power is provided from the AC
input power supply 202 directly to the output line 230 through the
fourth relay 258. According to one feature, the UPS 200 output
voltage at line 230 is maintained at about a constant level when
the UPS 200 mode of operation is transferred from the second green
mode option to an AC mains power input mode.
According to another embodiment, the UPS 200 includes a standby
mode option. In the standby mode, the main controller 218, the
communication circuit 214, the first LPS 210 and the main LPS 212
are powered on, while all other components of the UPS 200 are
turned off. For example, in the standby mode, the PFC 222, the
inverter 234, and the charger 220 are turned off. According to one
feature, the standby mode reduces the energy consumption of the UPS
200. In the standby mode, the output power is provided from the AC
input power supply 202 directly to the output line 230 through the
fourth relay 258. The first LPS 210 provides power to the main LPS
212 through the first diode 226. According to one feature, when the
UPS 200 enters the standby mode, the communication circuit 214
turns on the first LPS 210. According to another feature, when the
UPS 200 enters the standby mode, the main controller 218 turns off
the charger 220. According to one feature, turning off the charger
220 reduces tare losses, improving the efficiency of the
system.
According to another embodiment, the UPS 200 includes a sleep mode
option. According to one feature, in sleep mode, all the components
of the UPS 200 are turned off except the second logic power supply
208 and the communication circuit 214. The sleep mode option will
now be described with reference to the flow chart 350 in FIG. 4. To
enter the sleep mode, at block 352, the communication circuit 214
turns on the second LPS 208. The second LPS 208 may be an economy
LPS. At block 354, the communication circuit 214 determines if the
second LPS 208 is functioning. If the second LPS 208 is not
functioning, at block 360, the UPS 200 does not enter the sleep
mode. If the second LPS 208 is functioning, at block 356, the main
controller 218 turns off the first LPS 210 and the main LPS 212, as
well as the PFC 222, the charger 220, the battery 216 and the
inverter 234. In sleep mode, at block 358, the second LPS 208
provides power to the communication circuit 214. In one example,
the communication circuit 214 is coupled to a user interface, which
continues to receive power from the second LPS 208. A user may
interact with the user interface to control the UPS 200 to exit
sleep mode and either enter one of the other operational modes of
the UPS 200 or power the UPS 200 off. According to one example, the
power consumption of the UPS 200 in sleep mode is between about 5
watts and about 10 watts.
According to one embodiment, the UPS 200 may exit the sleep mode
and turn on the main LPS 212 when a user presses an ON/OFF button.
If the battery 216 is present and has a charge, the battery 216
will provide power to the main LPS 212 through the switch 224 and a
second diode 232. If the battery 216 is not present or is
discharged, and AC power is available, the first LPS 210 will turn
on and provide power to the main LPS 212 through the first diode
226.
According to another embodiment, the UPS 200 may exit the sleep
mode and turn on the main LPS 212 when the communication circuit
214 instructs the first LPS 210 to turn on. The request that the
UPS 200 exit the sleep mode may come from a Network Management Card
(NMC) or another available user communication port. According to
one example, the NMC may be a UPS NMC available from APC by
Schneider Electric. In one example, the communication circuit 214
may instruct the the first LPS 210 to turn on and cause the UPS 200
to exit the sleep mode to recharge the battery 216. In another
example, the UPS 200 may be programmed to turn on the main LPS 212
after a selected period of time to check the state of the battery
216 and determine whether to charge the battery 216.
According to another embodiment, the UPS 200 may exit the sleep
mode when AC mains power supply 202 is available by cycling the AC
mains power supply 202. In one example, cycling includes turning
the AC mains power supply 202 off and then turning the AC mains
power supply 202 on again. Cycling the power in one embodiment
initiates the process 350 described above with reference to FIG.
3.
According to one feature, when the UPS 200 exits the sleep mode and
the main LPS 212 is operational, the second LPS 208 is turned off.
The communication circuit 214 may turn the second LPS 208 off.
According to another embodiment, the UPS 200 includes an Emergency
Power Off (EPO) mode option. In the EPO mode, the second LPS 208,
the first LPS 210 and the main LPS 212 are powered off. In one
example, the UPS 200 may exit the EPO mode if the UPS ON/OFF button
(not shown) is activated. In another example, the UPS 200 may exit
the EPO mode if the AC mains power supply 202 and the battery 216
are removed.
The UPS 200 may be implemented as a single phase power supply, a
three phase power supply or as a split phase supply and different
embodiments may be designed to accommodate various input voltages.
Further, the UPS 200 may be implemented as a modular, scalable UPS
having multiple replaceable power modules and battery modules as
described in U.S. Pat. No. 5,982,652 and in U.S. Pat. No.
7,446,433, both of which are assigned to the assignee of the
present application and incorporated by reference herein.
Additionally, the UPS 200 may be implemented as an uninterruptible
power supply for providing power to a load as described in U.S.
Pat. No. 7,939,968, which is assigned to the assignee of the
present application and incorporated by reference herein.
FIG. 5 is a schematic diagram of another UPS 250 according to an
embodiment of the invention. The UPS 250 is similar to the UPS 200
and similar components are labeled with the same reference numbers.
The UPS 250 differs from the UPS 200 in that, for example, the UPS
250 includes a second input feed 252. According to various
examples, the second input feed 252 may be an AC mains input,
including a single phase power supply, a three phase power supply
or a split phase power supply. According to one embodiment, the UPS
250 operates in all of the modes described above for UPS 200 and
also includes a first bypass mode option. In the first bypass mode,
the UPS 250 receives input power from the second input feed 252. In
one example, the UPS 250 enters the first bypass mode after failure
of the AC power at input 240. The second relay 254 and the third
relay 256 are closed and the PFC 222 operates from the second input
feed 252. The PFC 222 outputs DC power to the charger 220. The main
LPS 212 continues to operate from the charger 220 output. According
to one example, the PFC 222 provides power at lines 242 and 244,
and the inverter 234 provides the output power at line 230.
According to another embodiment, the UPS 250 also includes a second
bypass mode. In the second bypass mode, the UPS 250 receives input
power from the second input feed 252. In one example, the UPS 250
enters the second bypass mode upon failure of the AC mains power
supply 202. In the second bypass mode, the communication circuit
214 turns on the first LPS 210, and the first LPS 210 outputs power
to the main LPS 212 through the first diode 226. The main
controller 218 turns off the charger 220. The main controller 218
may turn off the PFC 222. When the PFC 222 is turned off, the
second input feed 252 provides the output voltage at line 230
through the second relay 254 and the fourth relay 258. According to
one feature, turning off the charger 220 reduces tare losses, and
turning off the PFC 222 increases the efficiency of the UPS
250.
According to another embodiment, the UPS 250 may utilize a third
bypass mode of operation when input voltage is available at the
second input feed 252 and not available at the AC mains power
supply 202. In the third bypass mode of operation, AC voltage at
the second input feed 252 is provided through the second relay 254
and the fourth relay 258 to the output 230. The third bypass mode
of operation may be used in place of the battery mode of operation
to save battery life or may be used after battery mode when the
batteries have become partially drained. In one embodiment, the UPS
250 may also include a mechanical bypass switch coupled directly
between the second input feed 252 and the output 230. The
mechanical bypass allows a user to completely bypass the UPS 250
upon failure of the UPS 250 or to provide maintenance to the UPS
250.
Any of the preceding embodiments can be implemented within a UPS,
for example, a UPS having a DC battery as a backup power source.
The UPS may be configured to provide backup power for any number of
power consuming devices, such as computers, servers, network
routers, air conditioning units, lighting, security systems, or
other devices and systems requiring uninterrupted power. The UPS
may contain, or be coupled to, a controller or control unit to
control the operation of the UPS. For example, the controller may
provide pulse width modulated (PWM) signals to each of the
switching devices within the circuit for controlling the power
conversion functions. In another example, the controller may
provide control signals for the relays. In general, the controller
controls the operation of the UPS such that it charges the battery
from the AC power source when power is available from the AC power
source, and inverts DC power from the battery when the AC power
source is unavailable or during brown-out conditions. The
controller may include hardware, software, firmware, a processor, a
memory, an input/output interface, a data bus, and/or other
elements in any combination that may be used to perform the
respective functions of the controller.
In the embodiments described above, a battery is used as a backup
power source. In other embodiments, other AC or DC backup sources
and devices may be used including fuel cells, photovoltaics, DC
micro turbines, capacitors, an alternative AC power source, any
other suitable power sources, or any combination thereof. In
embodiments of the invention that utilize a battery as a backup
power source, the battery may be comprised of multiple batteries of
cells coupled in parallel or in series.
In one or more of the preceding embodiments, the switching devices
may be any electronic or electromechanical device that conducts
current in a controlled manner (e.g., by using a control signal)
and can isolate a conductive path. Representations of various
switching devices, and other electronic devices, in the figures are
exemplary and not intended to be limiting, as it will be
appreciated by one skilled in the art that similar or identical
functionality may be obtained using various types, arrangements,
and configurations of devices. For example, one or more of the
switching devices may contain one or more anti-parallel diodes, or
such diodes may be separate from the switching devices. As
indicated above, in some embodiments, the switching devices include
a rectifier, for example, a controlled rectifier that can be turned
on and off with the application of a control signal (e.g., an SCR,
a thyristor, etc.). Additionally, other devices, such as resistors,
capacitors, inductors, batteries, power supplies, loads,
transformers, relays, diodes, and the like may be included in a
single device, or in a plurality of connected devices.
In the embodiments described above, rectifier/boost circuits are
described for use with uninterruptible power supplies, although it
should be appreciated that the circuits described herein may be
used with other types of power supplies.
Embodiments of the present invention may be used with
uninterruptible power sources having a variety of input and output
voltages and may be used in single phase or multiphase
uninterruptible power supplies.
Having thus described several aspects of at least one embodiment of
this invention, it is to be appreciated various alterations,
modifications, and improvements will readily occur to those skilled
in the art. Such alterations, modifications, and improvements are
intended to be part of this disclosure, and are intended to be
within the spirit and scope of the invention. For example, the
gating pulses used to operate the switching devices of the power
converter may vary in frequency, duty cycle, or both. Further,
alternative configurations of electrical components may be utilized
to produce similar functionality, for example, inverter and charger
functions, or other functions. Accordingly, the foregoing
description and drawings are by way of example only.
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